Remodified Ni/Al ₂ O ₃ Catalysts for the Gas-Phase Reductive Amination of 1-Octanol: Reconfiguration of Acid–Base Sites Enhances Catalytic Performance

In industrial applications, the amination of long-chain fatty alcohols to synthesize fatty amines still faces challenges such as unstable reaction rates and low product yields. Therefore, developing a catalyst for the amination of long-chain fatty alcohols that achieves high yields remains a significant challenge. Herein, we report that a series of Ni–Re/Al2O3 catalysts were synthesized and characterized for the continuous gas-phase reductive amination of 1-octanol with ammonia under atmospheric pressure. The results indicate that the presence of Re not only promotes hydrogen spillover and accelerates the reduction of Ni species but also weakens Ni–O–Al interactions and reconstructs the surface acid–base properties. The resulting balanced distribution of weakly basic, moderately basic, and strongly basic sites regulates primary amine selectivity, with yield exhibiting a volcano-shaped relationship with Re content. Under the optimal conditions, the Ni-2Re/Al2O3 catalyst achieves 99.5% conversion and 64% monoamine selectivity. This study reveals the synergistic effect of Re in regulating metal–support interactions and acid–base sites, which provides a rational design strategy for non-noble catalysts in the reductive amination of long-chain alcohols.